Fender 30

Schematic(s) fender_30.pdf
Configuration: , ,
Production: ,

Model/Circuit Number: 30
Years of Production:
1980 – 1981
Era: Rivera
Configuration: Combo (1×12 & 2×10)
Controls: Black face plate with white letters
Knobs: Black skirted w/ chrome center, numbered 1 – 10

  • Front: NORMAL CHANNEL – Input 1, Input 2, Bright Switch, Volume, Treble, Bass. REVERB CHANNEL – Input 1, Input 2, Channel select switch, Preamp Gain with pull-knob boost, Treble with pull-knob boost, Bass with pull-knob boost, Reverb and Volume
  • Rear: Fuse (2A), Speaker out, Speaker out, Line Out Level, Lineout, RCA Pedal input for Channel switching, 1/4” Pedal input for Reverb control, Reverb Output, Reverb Input (RCA), Hum Balance control


  • Dimensions: 1×12: 24 1/2” x 18” x 8 3/4”, 2×10: 17½”x 23¾” x 9”
  • Hardware: Medium Chassis Straps 4 5/8”
  • Handle: Black Strap
  • Feet: Glides
  • Corners: Black Metal 2 hole with lip

Covering Material

  • Tolex/Tweed: Black Tolex
  • Grill Cloth: Black White Silver; Black with Metalic Silver Trim; Black Grill with White Trim

Logo: Grill Mounted, Chrome and Black Script Fender without tail
Weight: 40 lbs

  • Size: 1 x 12” or 2 x 10”
  • Impedance: 8 ohms
  • Model: 12” Fender Special Design 005379, or (2) 10″ – 8 Ohm CTS Speakers (137-8031) or 10” Fender Special Design(For more info, check out the Jensen Replacement Speakers)

Effects: Reverb
~Watts: 30 watts

  • Pre amp: 12AT7, 7025
  • Power: 2 x 6L6GC

Bias: Fixed
Rectifier: 5U4

Comments: – 6 Spring Reverb Tank – Dual Pedal Switch – Line/Recording jack – Hum Balance Control

44 Responses to “Fender 30”

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  1. Comment by Victordemise — July 17, 2011 at 8:36 pm   Reply

    I have one of these puppies (Silver Faced)- Needs work, but it is a sweet amp when it’s runnin right

  2. Comment by Guest — July 24, 2011 at 8:27 pm   Reply

    Fantastic Fender amp. tipical blackface Fender cleansl Sweet reverb, creamy overdrive sound . Recommended

  3. Comment by Nottfadeaway — October 22, 2011 at 5:58 am   Reply

    Pure Fender sound. Highly recommended. An overlooked Fender classic amp

  4. Comment by William HillNovember 19, 2011 at 7:20 pm   Reply

    The sounds from this combo are timeless,for anyone with pure appreciation of
    what tone is all about,this may be the the singularly most underestimated of
    all fender amp production ,look at the features :-all valve point to point wired,
    two speakers,reverb,channel select,voltage selector 30 watts ,so loud enough
    to gig with ,yet subtle enough for home practise,very tweakable features,, a
    priceless gem ,of subtle yet undeniable quality,,and becoming hard to find.

  5. Comment by Russwilbanks — January 10, 2012 at 1:12 pm   Reply

    I own and love this amp. Bought it used with a 12″ JBL E-120… replaced that with a jensen n series…. So much beautiful tone at club volume. My other main amp is a re-issue bassman, with replacement speaks (again Jensens)
    Some forums are saying this is  Fender 30 is NOT a Rivera design… any info on that?

  6. Comment by Guitarslinger56 — April 26, 2012 at 3:47 pm   Reply

    Mr. Rivera himself in a video interview has said that he was NOT instrumental in the design of this series. This series had a production run of almost 2 years. Mr. Rivera was hired by Fender after that. So,no they are not technically an amp made during his brief time at Fender.

  7. Comment by Blueguitar007r — June 12, 2012 at 8:17 pm   Reply

    Not Rivera era (wow a couple years is an era? And Rivera amps are shit) amp. Please put in correct category.

  8. Comment by Tim Aves — June 21, 2012 at 4:56 am   Reply

    I bought this about three months ago, having only ever seen one other like it anywhere in the world in the past 15 years, thinking it would be like a scaled-down version of the the Fender 75, one of which I also own and love. It’s not – it’s a TOTALLY different beastie!
    My amp tech pal John, who gave it the once-over reckons it’s based on the classic Deluxe Reverb, with channel switching and a few push-pull bells and whistles to make it look more modern and a beefier 6L6 output. Funny, if that’s the case, it’s a shame it doesn’t sound a bit more like a Deluxe. I’ve grown to rather love this amp, but to my ears, it doesn’t quite have the same classic Fender amp “shimmer” as the 75.  It’s a bit more middly, with a bit of a click on the front of the sound, reminiscent of some Marshalls – and odd comparison, I know, but that’s what I hear.
    Whatever, it’s a great little amp.

    • Comment by Jamie — July 27, 2012 at 1:23 am   Reply

      Tim – you lucky man – a 75 and a 30 ! Just picked up a 75 head and after new tubes its just great, I’m amazed actually.

      Quick question about tone boost knobs – do they boost at the current knob position only ? By which I mean the knob seems not to function when turned in the “out” or pulled boost position ?

  9. Comment by Crimhead — July 12, 2012 at 2:17 am   Reply

    I bought mine new back in 1980. I fell in love with it´s tone. from clear warm sounds (channel1) to blues stuff and even real overdrive rock sounds (channel2) it has it all. No need for another amp. Loud enough for club gigs (And I mean really loud) The 2 10″ speakers do a great job. If you find one along the road, test it. You won´t be disappointed by this raw gem.

  10. Comment by Mad dog — October 24, 2012 at 11:08 am   Reply

    I just acquired one of these on a swap deal and the tones it puts out are crazy. Bold and loud this amp is super versatile with real fender shimmer. I’d never even heard of them before now. Lucky find its in excellent condition just swapped out the Utah for a reissue p12n and now this amp really does sing.
    To think these go for the same dough as hot rod deluxes is a joke the comparison is a non starter.

    • Comment by William HillOctober 24, 2012 at 3:46 pm   Reply

      fender would do well to hear you,, and re-issue the 30,,and also do a 20 ,,and a 10 watt,,all with 2×10″ speakers,, and even put in power scaling too ,,its the way all amps should go,, :)(and even do a 2×10 5watter) ,,w/reverb,,all valve,,

  11. Comment by Mad dog — October 25, 2012 at 3:46 am   Reply

    Yeah for sure Will would be good if they brought them back so replacement parts could be s
    ourced but then these amps would no longer be exclusive and minorities (fortunate as we are!) like us would not be here marvelling at them!

  12. Comment by William Hill. — October 25, 2012 at 5:31 am   Reply

    Paul riviera was brought in by fender/cbs ,in `1981,,ed jahns was the man responsible for the design of the fender 75″ and it ties in historically that the “30” was probably his design too,

  13. Comment by Mad dog — October 27, 2012 at 2:23 am   Reply

    Anyone here know who sells a compatible foot switch for the 30? Aftermarket or fender not bothered. Thanks guys

    • Comment by William HillOctober 28, 2012 at 2:56 am   Reply

      Try on ebay M,D,,have seen plenty of useable switches on there, mine needs one as well ,,:)

      • Comment by Mad dog — October 28, 2012 at 10:40 am   Reply

        Thanks Will I’ve been having a look on ebay mate but it seems the foot switch for this pedal, like the amp is quite rare. Looks like it has a 1/4″and an RCA plug. Most of the switches I’ve seen have either two 1/4 or two RCA plugs. Wonder could one of those type pedals be modded to suit our amp?

        • Comment by William Hill. — October 28, 2012 at 7:19 pm   Reply

          Yes M,D thats just what i`m thinking,, have a double f/sw modded,, or failing that get seperate ones with an rca set up on one and the normal 1/4 on the other,, but i`d prefer the double modded one , i will get one and keep you posted if it works out,,:)

          • Comment by Mad dog — October 28, 2012 at 11:53 pm  

            Thanks Will let me know how you get on. I saw 1 on usa ebay but it was crazy expensive around $150 usd. Dont use 2nd channel that much but would be handy at times.

    • Comment by marco benvegnu — November 19, 2012 at 9:30 am   Reply

      dear mad dog, i’m servicing a fender 30 and i need a somo colse photos of the inside. can you hel me??
      thanks in advance

      • Comment by Mad dog — December 11, 2012 at 12:34 pm   Reply

        Hi Marco, I don’t have any internal photos I could give you mate. Never need to open it up.
        Their is a schematic on the top of this page tho that should help you out.

      • Comment by spdwaver1 — July 15, 2013 at 8:48 pm   Reply

        Did you ever get the photos you were after? I had taken several and sent them to my amp tech prior to having the Orange Drop-type caps replaced with Sozo blue molded caps.

  14. Comment by taffy — November 24, 2012 at 3:21 pm   Reply

    with roughly the same tube compliment as the 75, was this run PSE?

  15. Comment by marco benvegnu — February 4, 2013 at 6:07 am   Reply

    dear sirs,
    i’m servicing a fender 30 and i need some colse photos of the inside. can anyone of you help me??
    thanks in advance

  16. Comment by alamoampman — May 13, 2013 at 10:18 pm   Reply

    This Fender Amp is one of those well kept secrets that’s now just starting to come out of the dark. Grab one now while you still can…prices are climbing slowly on these…(and it’s bigger cousin the Fender 70)……. If you have the 2 / 10 version of the Fender 30, here is what I found out by trial and error… …..This amp works fantastic with a Tone Tubby Ceramic 50 watt and Eminence Legend 75 watt speakers. This combo allows you to keep the bass off or use very little of it giving you crispy clear lively rich tones. The first channel will sound like a Twin Reverb but not at 100 watts…great for country type blues licks, now roll the treble off a little work the mid and bass ( start without bass…roll it up very slightly if you need a little) and take out the bright switch and put your Jazz guitar in it now…wow! warn clear and well balanced running jazz scales and chords….

    Channel 2 can hit SRV territories ( without a TS 808) with this combination of speakers. Keep the bass off and pull out the treble knob kept at 6 to 10 and slowly work it out, keep the mid on 8, 10 … work your master and volume knobs to your volume. Now add a touch of reverb…You can get this tone loud, or low….you will learn the responses because your ear will tell you…man it’s sound good….I tried quite a dozen speakers combinations on it…all speaker were not cheap ones either…lol… Also, practically ANY distortion or overdrive pedals will sound great in this amp with this combo of speakers…You will be impressed.. because this combo of speakers makes this amp sing and sound bigger and fuller with out blowing the club down…I was told by a person that walked into the club…he thought I was playing out of a Super Reverb…. .Another gig a person thought it was the sound of twin reverb… Hope this helps in your pursuit of tone…thanks for reading. 🙂

  17. Comment by spdwaver1 — July 15, 2013 at 9:18 pm   Reply

    I recently traded a pristine Blues Deville 4×10 for an equally pristine closet-kept Fender 30 1×12. All original, down to the filter caps; tolex had not even one tear in it. The fact that it sounded almost horrible with the stock speaker in it (Oxford?), it did not deter me from trading for it, knowing that it was a completely handwired circuit which could be bettered by a the removal of cheap caps and addition of new filter caps and blue molded caps.

    I had the stock speaker removed in favor of a Weber Blue Dog AlNiCo, which actually sounds decent. It wasn’t my first choice, but it works for now. Ultimately, I know that it needs a Jensen, which I would gladly ditch the Weber for in a heartbeat, given the opportunity.

    I have read that this amp’s circuit was based on a Vibrasonic or Vibro-something, which may be true, but I will say this: I own an original ’64 Super Reverb (original, reconed speakers as well); this Fender 30 has THE blackface sound I have always loved. When the blue molded capacitors are broken-in, it will sound even looser with that nice (although slightly more mids) round bass note attack (SRV’s low ‘E’ final note) and chimey, clear cutting highs. It can get creamy as well, with the volume rolled back on a Strat equipped with treble bleed circuit.

    This amp takes certain pedals well. A Boss SD-1 with some mods, a DS-1 with diodes removed, TS-808 variants and — who knows what else. With the combination of a couple modified OD pedals, this amp produces nice sustaining lead tones – even from single coils. With the right speaker, perhaps an 80-watt, this amp can produce a lot of clean headroom. Having tested a Celestion “Seventy/Eighty” cabinet, I can attest to the fact that an efficient speaker would do this amp justice on the stage.

    Overall, this amp is destined to become a favorite of mine (with a Jensen in it) as well as a keeper.

    As mentioned several times, this amp is NOT a Rivera-era amp, nor does it have – for the sake of clarifying misinformation on the Internet – a linear transformer, like it’s bigger brethren.

    • Comment by Mad dog — July 22, 2013 at 11:01 pm   Reply

      You totally mugged the guy who got the deville hahaha what a score mate!

      • Comment by spdwaver1 — October 9, 2013 at 12:49 pm   Reply

        Thanks, and I agree – I went ahead and tried a couple Jensen speakers in it: both a P12N and a C12K; the C12K sounded best, but the Weber sounds the best out of them all. I am now going to sell or trade it, since I have a different custom-made Fender amp (Princeton-style) that is perfect in every way. This amp is perfectly set up and ready for another 30 years of service!

  18. Comment by Dave Pacho — April 12, 2014 at 3:28 am   Reply

    Hey all,
    I’ve had my 30 since 2000 and cannot agree with you more. It truly is a gem, by far the best amp I’ve ever owned. Producing amazing sound from clean tones for doing all the Motown classics to the crunchy sound I want went playing 70’s style rock.

  19. Comment by Ray B — May 24, 2014 at 5:54 pm   Reply

    Hi guys, I’m 67 yrs old and been playing guitar and bass since 1959. I’ve used a lot of amps in my day including but limited to:Watkins, Bird, Vox, Peavey, Gretsch, Musicman, Roland, Fender, Line6 but I always gravitate back to a Fender.
    I picked up my 1×12 Fender 30 amp from a long since defunct local music store in about 1984 and paid A$400 for it. Since then it’s done quite a bit of work and had couple of valve changes in its life. It has now developed a bad crackle when it gets hot so I guess it’s time for new caps.

    The Fender 30 is a very sweet toned amp and suits a broad spectrum of playing styles from country, rock, blues/ jazz etc. Very crisp and clean to dirty it does it all. My main guitar is a 62 Strat but I also use a Tele, a Gibson 355 BB King, Gretsch Country Gent and a Ricky 360 x 12 string. They all sound great through this lovely little amp.

    The 30 is certainly powerful enough for any gig I’m going to do now. In my earlier day it was miked up through the PA and all I heard was mangled fold back. Those days are long gone and with the pub/ club venues today being similar to those of the 60’s it’s an ideal amp. In any case my strength to carry heavy gear is waning and here’s no possibility of me lifting my Vox AC30 now, those Bulldoog speakers weigh a tonne. Funny that because when I was a skinny 75Kilo 19 year old I carried the AC30 with no problem at all. Now I’m 95Kgs and I can’t lift a thing.

    I would advise that if you can’t find a Fender 30 and I must say I’ve only ever seen one other, then go buy a Fender Deluxe. You might not get the versatility of tone that the 30 gives you but you will love it and when you’re old like me, you can still sit back and enjoy playing through it. Oh yes, and you will still be able to lift it too.
    ‘Keep on pick’n’

    • Comment by Kenny LeeJune 28, 2015 at 6:07 am   Reply

      Hey, Ray! Man, can I identify with you! Not many of us left!

      I started in 1961 (also 67), so you are one of the very few who have actually been in it longer than I have. My ears went south years ago (plugs, children…PLUGS!–At least on the drummer’s side!), and I recently had back surgery from the days I put my Twin up over my head and carried it through a crowd of people and out to the car. Thirty-five years of hoisting this stuff will get you, children, so watch your backs, too. As Ray says, about all I can lift nowadays, is my fork!

      I currently have a blackfaced silverface Twin, a blackface Showman, two blackface Super Reverbs, AND a Blues Deluxe … which are ALL too loud for my home! Trouble is, I am hooked on the 6L6 fat bottom end sound. I keep trying amps with 6V6’s, Class A EL84’s (Mesa, Traynor) … but nothing gives me the fullness of a 40 watt amp running on at least FOUR, a little towards the middle of the power amp stage. My ears can’t take that SPL anymore. And I can’t afford a Matchless or a Kingsley which are pretty full sounding even at a lower volume (my wife would freak if I sold any of my amps). A real quandary.

      Perhaps I’ll look around for a Fender 30 … I mean, it’s a savings of ten watts, right?

  20. Comment by AndrewAugust 20, 2014 at 5:19 pm   Reply

    Scouring the internet looking for proper tube replacement for this particular amp. Bought it three months ago maybe more. I love this thing to death. I spend 400$ on it at guitar center. Looks old but sounds like a howling blues demon. I love it with all my heart and soul. But…. My girlfriend broke the power tubes. So…. I went from replacing with the same 6L6Ge tubes for the two power tubes but…. For the rectifier (I think that’s what it is) guitar center guys suggested a 5ar4 in place of a 5u4 that was there previously… My amp cut out volume about two weeks later. Half volume…. Like 1-10 volume is the same. when this thing is on 2-3 it’s CRANKING any advice?!???

  21. Comment by AndrewAugust 20, 2014 at 5:20 pm   Reply

    I’d love if you guys could reply to me. Or email me or even a text maybe? I’m just young lad who likes Robert Johnson and black sabbath and zeppelin and soundgarden and I want to plays amp 🙁

  22. Comment by Flem — June 3, 2015 at 8:33 am   Reply

    Another mega +1 for all the above who state that this is a hugely underrated Fender amp. Think of it like a hand-wired Hot Rod Deluxe, but better. The Normal channel is voiced like my silverface Princeton Reverb. Then you can dial in just about any classic overdriven Fender tone and beyond with the Reverb channel. Works well with all guitars and contrary to other Fenders I’ve owned (including standard-bearers like a 60s Deluxe Reverb, 70s Deluxe Reverb, 70s Vibrolux Reverb, etc.) this puppy sounds good at reasonable volumes. My only knock against this amp is that the reverb seems voiced differently from the classic Fender reverb we’ve all grown up with. A bit more restrained than the classic lush Fender reverb sound, but by no means unpleasant.

    20 years from now everyone will recognize this as the overlooked gem that it is. Buy one now if you can find one.

  23. Comment by Larry — August 26, 2015 at 9:53 am   Reply

    Reading all of the comments above have been truly enjoyable. I’ve owned & gigged with the Fender 30 since 1980. The amp has been a real workhorse over the years. The only thing I’ve ever really had issues with on the amp was the design & stability of the “Switching Circuit” (I think that’s what it is at least). The amp would start crackling during use (from heat and vibration I guess). After visiting a repair shop the first time, I learned to just carry the repair tools with me and fix it between sets when needed. Other than that I’ve replaced the transformer once and re-tubed it to matched Mesa tubes (much fuller sound to my hears). I also add tilt legs to it because in most rooms I play, I run it as my monitor and feed the signal out of the rear into a PA system (seams to work best for small rooms/low volumes). The amp has some real volume and works great outdoors too. I’ve never regretted switching from my Ampeg VT-40’s & even Port-a-flex’s to this Fender. My 30 is the 2 10 configuration.

  24. Comment by Dietmar — August 31, 2015 at 6:10 am   Reply

    Got one for $400 from yard sale, replaced the 5U4 rectifier tube with a GZ34, changed one resistor and removed two capacitors to “blackface” the amp – you don’t get any more bang for your buck. The schematics supplied here were invaluable for that, soundwise it is somewhere between BF vibroverb and vibrolux, but without tremolo. I added a push/pull bypass for the master volume, but there is almost no difference between cranked master volume and no master at all.

    I also swapped the CTS 10” with Jupiter 10LC’s but might go back to the CTS. Mine has the “BF” cosmetics. I would never sell this amp, and if it got stolen, I would get another asap.

    • Comment by Jules — September 15, 2015 at 10:27 am   Reply

      Hi Dietmar, please can you confirm exactly which resistor and capacitor values you changed/removed to blackface your amp? I would really appreciate that, thanks. I purchased a 2×10 1980 silverface model from ebay in the UK about 1 month ago and just got it back from “sensitive” servicing. By sensitive servicing I mean that my amp tech does not automatically change filter caps unless they are bulging or leaking or the amp is obviously noisy, has an odd frequency response or is lacking power which it isn’t in my case. He changed the channel switch, two power valves, 1 pre, plus a new 5u4 rectifier valve. The amp currently stands me at £500 which was £350 for the amp plus £150 for servicing. These amps are extremely rare in the UK. Only about 1350 were ever made in the world, apparently. I am something of an amp nerd and experimenter with 8 currently on the go and had never heard of these until one month ago. For anyone interested the amp tolex had aerosol paint spatter which after trying all sorts of solvents I cleaned off with graffiti remover gel spray followed by “armour all” car spray after a few minor superglue and sharpie touch ups. The tolex is now gleaming and the amp is in overall great shape for 35 years old. I also modified a new twin reverb footswitch (the one with two rca(phono) jacks – one on a single core white cable and one with a central white cable plus external earth braid) to control to reverb and channel switching as follows: get a right angled stereo jack, a short piece of hook up wire about 3″ long and some heat shrink/self amalgamating tape/back insulation tape. The existing phono on the braided 2 core cable will control the channel switching. Cut off the phono jack on the single core white cable. Solder your piece of hook up wire to the braid of this cable at the phono plug. Do not try soldering it further down the braid as you will melt the central white core wire (I did!). Run the hook up wire down the braid and back up the other side of the “Y”. Solder the white wire that you have cut the phono off to the central tag of the stereo jack (ring of TRS). Solder the hook-up wire that you have added to the outer earth tag (sleeve). Before soldering this leg you may wish to add heat shrink tubing or you could just use black insulation tape on both legs. The newly added stereo jack will switch the reverb on and off. Re-label the footswitch. The footswitch works perfectly although of course there are no LED indicators unlike the original footswitch, which are now impossible to purchase unless custom made. Don’t use a straight stereo jack as it will stick out too far from back of the amp. I hope someone finds this useful. My initial thoughts are that the amp has a lot of potential but needs work. I don’t have any really classic amps to compare with but I’m also in parallel trying to optimise a ultralinear 70w pro reverb with JBLs from the same year (heaviest combo ever at 44kg – 30kg after 2 eminence lil texas, but thats a different story). Anyway, I think the 30 has a lot of potential but also do think it may be suffering from some 35 year old components at present. My interest is sparkling cleans plus with clarity and presence plus very light amp generated edge of breakup sounds for rockabilly and country. I use a slapback delay and trem pedal and nothing else. I find all overdrive pedals (including so called “true bypass”) I have tried so far to interfere too much with pristine and natural clean sound of an amp and prefer tube generated overdrive from the amp itself. I can also live without reverb on any amp, as a use the slapback delay pedal. Channel one sounds very good but not world class already. Maybe lacking a bit of blackface high end sparkle and presence, which hopefully Dietmar can help with? Perhaps slightly mid heavy. Good with a strat and tele, but my single coil gretsch 5129 comes accentuates the low mids. Channel two needs work and is a bit woolly and is lacking overall detail at present. Pulling the treble boost knob is equivalent to a bright switch and I will leave this permanently engaged for my preferred sound. The mid and bass boost knobs are currently totally useless on channel 2 as they completely overwhelm the sound with mush. The component values may have drifted. The reverb also currently does not stack up to that on my pro reverb and is a bit generic sounding and lacking in presence overall. Channel 2 also currently sounds quieter than channel 1, lacking presence with something of a veil over the overall sound. Component drift? I am hoping to improve this and think that overall, the amp is a keeper. The original fender speakers are pretty good, but I might try a pair of WGS G10c or even Celestion TEN 30’s at some point. I have tested the amp through a range of different 12″ speakers by plugging it into my other amps and using them as speaker cabs. This is simply achieved via a speaker cable(not signal cable) and a double ended 1/4″ mono jack socket adaptor. Fender amps with a 4ohm output can generally tolerate being plugged into an 8ohm speaker without problem (although there is a small risk of flyback voltages if cranked due to impedance mismatch). For anyone interested speakers and V1 preamp valve selection (plus general preamp “tube rolling” even of the same type) can make a huge difference to the sound of any amp and if you use effects powered off a 9V power supply, different 9v power supplies can also significantly change the overall tone and response of the amp, try it!. Another interesting fact that might be useful to put people’s minds at rest if trying external speakers is that old Fender amps like the 30 using shorting jacks on the main speaker output (N.B. but not the extension speaker output). What this means is that if you ever inadvertently run the amp with no speaker connected for a few seconds, contrary to common fears, you will not immediately blow the output transformer, you will just cause a bit of tube wear and tear and some transformer heating. This is a very useful safety feature of old Fender amps (unlike old Marshall amps which will blow the OT!) which should be more widely shared. Sorry for my very long blog, but I hope someone finds some of this interesting and useful. If anyone can kindly recommend any simple and reversible component mods for this amp, without hacking it about too much would, I would be very interested and grateful. Thanks.

      • Comment by Dietmar — March 15, 2016 at 5:25 am   Reply

        Jules, forgive me the belated response.
        What I did was this: Remove the two “cathode bias” capacitors of 2000 pF connecting the pin #5 on the output tubes. In my case, someone already exchanged the two and substituted with a 500 V 2000pF capacitor.

        Change the 680 Ohm resistor in the phase inverter that is connecting pin # 3/8 of the 12AT7 pi tube with the two 1m resistors to 470 Ohm.

        Swap 5U4 tzo GZ34/5AR4 tube rectifier.
        After that, your amp is very close to blackface vibrolux ab864 schematics and sound, but with a little more headroom and a bit more gain in the preamp due to higher cathode voltage in the preamp tubes (+210 V vs +170V in the vibrolux) and PI tube. I liked it, it sounds a bit more “surfy” and less “bluesy” and kept it. If you want more crunch or compression, you might want to change the voltage divider resistors to lower these voltages.

        Also, I disconnected the whole channel switching unit. No one needs it and it was ill designed anyway. I kept the connection of channel switch enabling to the preamp tube, so enabling channel switching will disconnect V1. This will give you more gain in V2 as found in the “Cesar Diaz Mod” but I never use this.

        Keep the original CTS speakers if you still have them. They’re rad. I use ONLY JJ tubes. Any chinese or russian tubes I used before broke soon. I am not related to JJ in anyway.

        In my amp, there was no need for recapping or elko leakage. This is not only the cheapest Fender I ever bought, but also the LIGHTEST and BEST SOUNDING. Next thing I will do is replace the output transformer. I think these were very cheap in the late silverface amps including the Ed Jahns designs.

        I hope I have answered all you questions accordingly.

        • Comment by Dietmar — March 15, 2016 at 10:54 am   Reply

          Sorry make that “higher plate voltage” of +210V vs +170V in Vibrolux AB964 instead of “cathode voltage”. I hope I did not confuse anybody. Accordingly, substitute higher loading resistors if you want more compression.

  25. Comment by StratopastorJanuary 23, 2016 at 5:59 am   Reply

    hi, I’ve notice people looking in vain for the footswitch-wiring for this amp.

    I deduced what the footswitch schematic should be from the amp schematic. A contact of mine has built it and it works with his Fender 30, so here you go…


  26. Comment by Jules — April 1, 2016 at 8:25 am   Reply

    Hi Dietmar, Thank you so much for replying in detail to my question about how you blackfaced your amp. I really appreciate all the time and trouble you went to give me a detailed description of how you did this. It means a lot to me and actually turns out to be perfect timing!
    I have been enjoying my 1980(?) 2×10 model with silver grille cloth a great deal after swapping out the original speakers, which I’ve kept, to Jensen Jet Tornado Neo 10’s, plus some tube rolling. Wow, I didn’t realise until recently how interactive ALL of the 12A…7 valves were in Fender amps! The speakers in themselves added sparkle, clarity and punch and shaved some weight off the amp (now 24kg). Compared with the Eminence Lil’ Texas neos which I have in a couple of other amps, which are also great but sort of neutral sounding, I feel the Jensens have an even clearer, more natural and more vintage sound and deliver tons of punch. I feel Jensen’s dB rating on these is conservative and they are a perfect match for this amp. The amp is plenty loud enough for any gig I do, especially as I often trickle a small amount from the amp line output into the desk to balance out the overall band sound.
    Anyhow, I just took my amp to Nigel at Matterhorn Amps in the UK (A real gentleman, excellent amp builder and repair man – highly recommended to anyone!) due to a buzz on Ch1. Unfortunately he found that the mains transformer is shorting out across the 5V winding, putting 147 volts across it. So my mains transformer and rectifier tube are effectively toasted! He felt that aside from age, 5u4s have a relatively high current draw at around 3A and this may have helped with the demise of the transformer, especially, if as you say it may not be the best quality in the first place. Maybe I just got unlucky with a 36 year old amp, who knows! Apparently, however, GZ34s have a lower current demand.

    So in light of my toasted mains transformer and your comments, Nigel has ordered an uprated Hammond unit for a vibrolux, will change the rectifier tube to GZ34 and do the PI resistor mod you mentioned. He said he didn’t find suppressor caps in my particular amp. I am happy to keep the channel switching circuit for the moment, but hopefully with the new tranny, GZ34, PI mod and re-biasing in conjunction with the existing jensen neo speakers, I should hopefully end up with a really great sounding and reliable amp at the end.

  27. Comment by Unclejam — September 23, 2016 at 3:59 am   Reply

    Hi guys, thanks for the useful info on here. I have just got my hands on a blackface “30” 2×10 and wondered if anyone has any idea on a current market value? The amp is in slightly unloved condition but works ok.
    The seller is inviting offers but its tricky to know as they are rarely for sale. Any help gratefully received.

  28. Comment by Mc McCarthy — February 9, 2017 at 3:07 pm   Reply

    I picked up one of these about 25 years ago for $150 in a pawn shop. Previous owner had cut the speaker section off the cabinet turning it into a head. It looked like it came from the factory that way and always had people asking what the heck that killer sounding amp was. I yanked the tube rectifier and through in a GT solid state one and the amp turned it to a real monster! I’d recommend trying it to anyone.

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